Longitudinal Evaluation of the Efficacy and Safety of Divalproex and Lithium in Dual Diagnosis Bipolar Rapid Cycling: This study recruits males and females age 18 and older who currently meet diagnostic criteria for rapid cycling bipolar disorder (type I or II) and who have met the criteria for substance abuse or dependence of cocaine, marijuana and/or alcohol within the past six months. Patients are initially stabilized on dual therapy of lithium and depakote and then randomly assigned to double-blind treatment with either lithium monotherapy or continued dual therapy. Patients remain in the study for six months or until they experience a relapse. Patients in this study are required to bring a friend or family member to all study visits as well as attend chemical dependency services. This study is sponsored by the NIMH. Subjects receive study-related care at no cost.